Automatic voltage-regulator.



G. A. BURNHAM. AUTOMATIC VOLTAGE REGULATOR. APPLIOATION FILED SEPT. 7, 1909.

Patented Apr. 4, 191 1.

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G. A.- BURNHAM. AUTOMATIC VOLTAGE REGULATOR.

. APPLICATION FILED SEPT. 7, 1909. 988,441

Patented Apr. 4, 1911.

2 SHEETS-SHEET 2.

2 UNITED STATES PATENT OFFICE.

GEORGE A. BURN HAI W, OF ESSEX, MASSACHUSETTS, ASSIGNOR TO SEARS B. CONDIT, J'B., OF BOSTON, MASSACHUSETTS.

AUTOMATIC VOLTAGE-REGULATOR.

Speeificationof Letters Patent.

Application filed September 7, 1909.

Patented. Apr. 4, 1911 Serial No. 516,428.

To all whom it may concern: Beit known that I, Gannon AJBURNITAM,

' a citizeh of the United States, residing at Essex, in the county of Essex and State. of Massachusetts, have invented an Improvement in Automatic Voltage-Regulators, of which the following'description, inconnection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

' My invention is a voltage regulator, whose object isto provide such a high degree of efiiciency that the introduction of the regulator into a Working system will not be liable to interfere'with the continuity of service. Up to the present time it has frequently been the case that the introduction of a voltage regulator would'render the operation of the system more uncertain'than it was without the'regulator, because of the possibility, and

- in "fact liability; of the-regulators refusing to work at a critical momenton account ofthe ireezlngof the contacts. my lnVGIltlOIl aims to provide a regulator which practically eliminates the tendency to I impair or destroy the continuity of service,

and I accomplish this by introducing means which is responsive to changes in voltage in the main line to cut in resistance into the field circuit 111 such a-m'annerthat 1t 1s practicallyimpossible for the make-and-break device to stick, bug, or freeze, irrespective :of

whether the interruptions are rapid'or slow.

' I provide a moving and preferably rotating contact or pair of coritacts, cooperating with a'reciprocating contact or pair of contacts, having relative frictional engagement.- The result" is that my voltage regulator has a =ferred embodiment of the invention; and

Figs. 2 and '3 are similar'views showing modified constructions. Itwill be understood that my mechanism is adapt-e'cltoa variety "of-uses and wiring 5 I Q i r arrangements, and'that I -h ave herein shown the same in connection with a generator and its circuit, merely as ameans of making the Accordingly,

I invention clearly intelligible. As shown, the

generator to be regulate-dis indicated at 1 connected in usual manner to feed wires 3 supplying current to a load 4, said generator having a usual field 5. Across the circuit 2, 3 is connected a voltmeter 7 whose needle 8 connects with any suitable sourceof supply, as a battery 9, by means of a wire 10, the wire '11 from the opposite end of the cooperate alternately with rotary contacts 23, 24 faston insulated pivots 25. :Brushes 26, 27 connect from the rotary contacts 23, 24

respectively with resistances 28, 29 connected by a wire 30 in series with thefield 5 of the generator 1, said circuit being completed from the opposite side of the generator b i a wire 31 to the contact lever 20 at 32. he condenser 6 is shown as connected "across from the wire 30 to the wire 3l.'- To rotate the contacts 23, 24, I mount loosely on the pivot 19 of the oscillating conta-cts'21, '22; a

ratchet gear 33actuated by a pawl 34 mounted on any adjacent moving part', asfor 'in stance on a stem 35 extending rigidly from tlielever 20. Said ratchet gear 33- en'gages a pinion 36 ona shaft 37 which also carrles a gear 38 in mesh with gears 39, 40 fast on the shafts 25 of said rotary contacts, whereby the'latter are driven.

electromagnets 13, 14,.

In the construction shown ill Fig. 2, two concentric disks or rotary contacts 44, 45 are .mount'e'd on a continuously driven shaft 46,

said disks being'shownas composed of can:

doctor material; 'Qotiperating therewith is a single contact 47'pivotally-mou ted M48.

and provided with a stem or recip1ocator 49 of magnetizable material corresponding in construction and function to the same part {35 in the preferred construction, the resist- The stem 35 is of magnetizable materi'ahheld' by a spring 41' and adapted to be attracted to one side or the other by tl1e cores42, -43 ofthe adjacent an-Jc'; 2 bring xtcrnal of thesc rotary mcu'ibcrs =1 l. '13. In tll'. construction shown in Fig. 3. instcad of the two wheel-like contacts pitm'ionsly tltEStJllbOL'l; a hollow or box like rotary i'nenihcr 50 is provided on a motor driven sha ft. 51 the same as in Fig. 3 and containing the two resistanccs 25, JD connw'tinc; to a peripheral contact ring 5:2 cnaged lo) a brush fiil of the wire 20. A t. thcir opposite ends said re istant-cs conncct to fa e rings 56, 5'7, engaged by contacts 58, of It rock bar ('30, the same in constriurtion and operation as the corresponding parts already described with reference to the construction of Fig. 1. In each instance the vibrating member has two contact surfaces which ongage alternately the cooperating two separate contacts which'are connected to the respective resistances. In Figs. 1 and 3, these two surfaces are at the ends of the centrally pivoted vibrating cross bar or head of the .vibrating member, in the form of two con- ..rlucting blocks, whereas in Fig". 2 these two surfaces are formed by the opposite sides of the single intermediate block 47. By providing these two separated or distinct surfaces, one cooperating with one rotating portion and the other cooperating with the other rotating portion of the cooperating contact parts, neither surface is called upon to do an excessive amount. of work, the work being divided between the two, and hence the-life of the contacts is increased.

In operation, the rotary contacts operate to bring anew make-and-break surface in position at each movement of the reciprocating contact or contacts, so that the ap;

.paratus continues to operate uniformly and without liability to stick or freeze. The rotary contacts of all three embodiments of my invention are moved, in each instance. previous to contact with the vibrating member so as to bringa new surface into contactqn-aking position, said previous movement.- in Fig. 1 being .a' step-by-step movement, and in Figs. 2 and 3 being a continuous movement of the rotary member or members. InFig. .1 the step by-st-ep movement is accomplished directly in connection with the vibrating member or other contact, whilein Figs. 2 and 3 the continuous rotating is accom plished by an externally driven continuously rotating shaft. The double-ended vibrating contact member of Figs. 1 and 3 has the ad vantage ofprolonging the life of the instrument, inasmuch as the two contacts divide the worlcbetwecnthem, and the same is accomplished by the operation of the double sided .bloek47 in Fig. 2. \Vheucver there is a variation-1n potential inthe mam circuit 2, 3, thereresnlts a corresponding move-v ment-in the; voltmeter 7 causing the needle 8' to move to the right or left, thereby energizing one or the other of the solenoids 13, 14

so as positively to move the contact lcvcr 30.

in a. corresponding direction. bringing its contact or contacts into enaagczncnt with the rotary contacts ii-i. 24;. as the case may be. of t'lto-malce-andbreak device. This cuts in one of the resistances "28, Qt 'and cuts out the other. ctirrespondingly changing the value of the field flux. The provision of the two 1'e sistanccs 18, 53!) of different values in connection with the nican described for cuttingout one and cutting in the othcr, or vice vcrsa, results in a furthc advantage. The values of said resistances is either too high or too low to give normal voltage at the generator. By introducing the resistance 29, as distinguished from short-circniting the resistance I am able materiall to redu e the tcinlcucy of sparli'ing at thc break between the reciprocating contact and one or the other of the rotary contacts, as the case may be.

As the mechanism shown in Fig". 1 is the preferred mechanism,asdcfincd in this speciiicat-iomI have not herein claimed the features which are specific to Figs. 2 and the same being claimed in my applicationserial No. 584,725, filed Sept. 30, 1910.

Having described my invention, what I claim is:

1. In a voltage regulator, twov relatively movable-cont'act members, having a relative movement into and outrof contact position and a transverse movement for bringing a new surface into contact position, and mechanism to move one contact with relation to the other in said transverse direction previous to. their relative movement into contact with each other and while the contacts are separated, andthen to move one of said contacts into contact with the other.

2. In a voltage regulator, .two relatively movable contact members. having a relative movement into and out of -contact pos tion .2l11l5111 to move one contact with relation to the other in said transverse direction-previous-to their contacting movement and to move one of said contact members intocontactjvith'the other in thetinieinterval between two transverse movements.

LI no. voltage regulatona rotatable contact member and a vibrating contact member. and mechanism to rotatesaid first named I contact member, previous to contact with the vibrating member and while the" I msm actuated'by therocltmg movement of contacts are separated to bring a new surface into contact position, and bring said vibrating contact member into engagement with en id rotatable c ntact l'nembcr.

.3. In a voltage regulator, a rotatable contact member and a vilirating contact mcmber, and nav-hantan to rotate said rotatable contact member after the separation of said two contact members to bring a new surface into contact position and bring said vibrating contact member into engagement with said rotatable contact member.

(3. In a voltage regulator, a rotatable contact member and a vibrating contact member. and mechanism to rotate said rotatable contact member previous to contact with the vibrating member and to move the vibrati ng memberin the time interval between two rotary movements.

7. An automatic voltage regulator, comprising a rotary contact mechanism having two rotary contact portions insulated from each other, a separate resistance for each portion. and a movable contact member movable to make contact alternately with one of said portions and then with the other to ren der said resistances alternately effective.

8. An automatic voltage regulator, comprising a rotary-contact mechanism having two rotary contact portions insulated from each other, a separate resistance for each portion, a movable contact member movable to make contact alternately with one of said portions and then with the other to render said resistances alternately effective, and means operated by said movable contact member for actuating said rotary contact mechanism.

9. An automatic voltage regulator, comprising an intermediately pivoted contact member, electromagnetic means for rocking said member on its pivot, a cooperating contact mechanism having separated contact portions to cooperate with the opposite ends of said pivoted contact member as the latter rocks on its pivot, a high resistance in series with one of said contact portions and a low resistance in series with the other of said contact portions.

10. An automatic voltage regulator, comprising an intermediately pivoted contact member, electromagnetic means for rocking said member on its pivot, a cooperating contact mechanism having separated contact portions to cooperate with the opposite ends of said pivoted contact member as the latter rocks on its pivot, a high resistance in series with one of said contact portions, a low resistance in series ith the other of said contact portions, said two contact portions be: ing movable with reference to the pivoted contact member for bringing new contact said pivoted contact member to move said two contact portions. i

11. An automatic voltage regulator, comprising an intermediately pivoted contact member, electromagnetic means for rocking said member on its pivot, a cooperating contact mechanism having separated contact portions to cooperate with the opposite ends of said pivoted contact member as the latter rocks on its pivot, a high resistance in series with one of said contact portions, a low resistancc in series with the other of said contact portions, said two contact portions having rotary movement. with reference to the pivoted contact member for bringing new contact surfaces into operative relation with the pivoted contact member, and moving mechanism actuated by the rocking member of said pivoted contact member to rotate said two rotary contact portions.

12. An automatic voltage regulator, comprising an intermediately pivoted contact member, electromagnetic means for rocking said member on its pivot, a cooperating contact mechanism having separated contact portions to cooperate with the opposite ends of said pivoted contact member as the latter rocks on its pivot, a high resistance in series with one of said contact portions, a low resistance in series with the other of said contact portions, said two contact portions having rotary movement with reference to the pivoted contact member for bringing new contact surfaces into operative relation with the pivoted contact member, and apawl and ratchet mechanism actuated by said rocking member to rotate said rotary contact portions.

13. In a voltage regulator, a contact member having two operative contact surfaces, two contacts to cooperate alternately with said respective surfaces, mechanism includ ing means operatively related to one of said two contacts for raising the voltage controlled by said regulator and including means operatively related to the other of said two contacts for lowering the said voltage, and operating means for said contacts.

14. In a voltage regulator, a common vibrating contact member, two contacts, mechanism including means operatively related to one for raising the voltage controlled by said regulator and .including means operatively related to the other for lowering the voltage, and means for moving said vibrating contact member into alternate engagement with said two contacts.

15. In a voltage regulator, two separate contacts, mechanism lncludmg means connected with one of said contacts for raising the voltage being regulated, and including name to this specification, in the presence of means conuectndwvith the other of suid contwo subscribing Witnesses. tarts for lowering the sui l VOitflfE, and a 1 w 1 third (Zl'rlliiltt uuzinhcr having tu contact (IPJORUIL BURBHAM' 5 surfaces to coiipurute ultemateiy with the Witnesses:

aforesaid scpm'nte contacts. -M. J. SmLnms,

In testimony whereof I have signed my EDWARD MAXWELL. 

